Prop modifier for v-model

[CyberAP]

Add a prop modifier for v-model to simplify wrapper components.

Rendered

[backbone87]

Ref #21

[CyberAP]

Ref #21

Thanks for linking a related issue. I knew someone has already proposed that!

But there are some key differences from the #21 proposal that I'd like to mention:

• Prop modifier for v-model #140 is promoting explicit behaviour compared to implicit in Transparent v-model #21
• at the moment Transparent v-model #21 was proposed there was no first class support for modifiers in v-model and multiple v-models. With the new v-model API it can be even more challenging to wrap components that accept multiple v-models.

[victornpb]

I really like this, wrapping something should be just as easy as "wrapping it"!

[yooneskh]

I absolutely support this and this is the best among rfcs about this problem. This really reduces a lot of code when we wrap things.

v-model is already (presented as) a syntactic sugar for binding and emitting, so a modifier for v-model would modify the syntactic sugar a bit.